"We feel great about this momentum, and our goal is to double the size of the services business in the next four years," Cook said.

To put that in context, Facebook, one of the world's largest software companies, generated about $7 billion in revenue in the third quarter.

December was the App Store's best month ever, with $3 billion in sales, Cook said. The developer community — the key to Apple's sustained software success — has earned a total of $60 billion, Cook said.

The number of users of Apple Pay have tripled over the past year, Cook said on the conference call, with transaction volume up 500 percent, year over year.